Prunus domestica is a plant of uncertain origins, it is presumed to come from the regions of south-east Asia. Introduced and cultivated in Europe for over two thousand years. The plum tree is divided into two groups geographically distinct from each other: the European plum and the Sino-Japanese plum. The European plum tree has dark green and rather thick oval leaves with a slightly hairy underside, the flowers that sprout before the leaves are white.
The fruits, apart from a few varieties, are generally oval-shaped with colors ranging from yellow, green, red and violet-blue. Often the pulp detaches from the stone and is used both for fresh consumption and for drying, their laxative power and the high quantity of sugars are also known, which give the fruit an excellent nutritional value.
The Sino-Japanese plum has light green lance-shaped leaves, very thin, the flowers are white and flowering occurs earlier than the European plum. The fruits are generally round in shape, the color varies from yellow to red to blue-black and are cultivated exclusively for fresh consumption.
The myrobalan is usually used as a rootstock for the plum tree, which gives the plant a remarkable development and good longevity. Productivity is excellent and has no particular land requirements. Another rootstock is the San Giuliano plum tree which has an excellent graft affinity, good productivity. For the Chinese-Japanese plum varieties, also the peach tree is used as rootstock, which makes the plant very productive, but less long-lived.
Other interesting rootstocks are the franc, which behaves very well and allows you to have healthy and vigorous plants and the Pixy. Depending on the type of rootstock chosen, plants of different heights and suitable for substrates with variable characteristics will be obtained.
In most cases, European plum trees are self-fertile, however the presence of different varieties greatly increases their fruit production. On the other hand, many Chinese-Japanese varieties are self-sterile, so it is often necessary to plant two or more varieties able to fertilize each other, of course it is essential that they bloom in the same period. In many cases the plum trees, after flowering, produce more fruits than those that the plant is able to bring to maturity. To obtain a good production it is recommended the thinning of the small fruits.
As for many other plants, also for the plum tree it is recommended to use organic fertilizers such as manure or manure during the vegetative rest period, while in spring-summer, NPK fertilizers can be used, ie nitrogen-based, phosphorus-based and potassium avoiding to use them during the hottest and dry periods.
The animal parasites that most attack the plum are in particular the aphids, which develop on the ends of the shoots. Possible are also attacks of cochineals which, if present in a massive way, can cause a general weakening of the plant with damages to the fruits. Another parasite that causes significant damage is the plum moth that lays the eggs in the leaves and in the fruits causing an early fall.
Pathogens of fungal origin to which the plum tree is subject is the corineum which produces spots on the leaf that necrotize the tissues leaving them pricked.
Forms of farming
In full wind
The plum tree is a tree typically full wind (natural growth). It is possible to form the crown on a medium stem at about 120 cm, or with a tall stem at about 180-200 cm.
Starting from a sucker of a year just planted, you will have to immediately cut it to the desired height, after which, the following year, at least three branches will be preserved which will have to be shortened to 20-25 cm from the starting point, these will produce to them turn other branches that will also be shortened. By doing so, the trunk will be strengthened and the branches that will grow later will be sufficient to form the final crown. Afterwards only internal thinning of the foliage and elimination of dry or damaged branches will be done.
A dwarf vase
To form the pot it is necessary to plant a sucker for one year and cut it at 40-50 cm from the ground. At the beginning of the second year at least 30 vigorous branches will be shortened to 30-40 cm, keeping them away from the center, which in turn will give other branches of which only the external ones will be preserved. Also shorten these branches again so as to further strengthen the plant, after which the growth will be left free by practicing only some thinning pruning eliminating the disordered branches.
A palmette or espalier
This type of shape is very useful in case you want to decorate walls or fences. In this case you will have to plant a sucker of one year cut at 50 cm from the ground and the following year keep at least four branches, arranging them on two planes and anchored to a support, which can be a wire supported by two posts on the sides of the plant or a trellis. For this type of shape it is recommended to use low or medium growth varieties.
Susino - Prunus domestica: Susino
For the cultivation of prunus domestica It is good to respect some indications on the exposure and the type of terrain; this plant is quite rustic and resistant, so much so that in the period of vegetative rest it can withstand without particular damages temperatures that can even reach -15 ° C. The planting of these plants should take place in the autumn, before the temperatures drop and there is the danger of frost. The best soil for cultivation is the one rich in organic substances, draining and not too heavy, even if, given the rusticity of the plant, the prunus domestica it can also grow in compact soil with a high percentage of clay; fundamental, however, is that the substrate does not allow the formation of water stagnations that could cause radical rot. This variety adapts well to different environmental conditions and can withstand even in warm environments. The exposure, in order to have an abundant harvest, must be in full sun. It can be damaged if late frosts occur. For young plants it is good to proceed with constant watering, especially in the hottest periods of the year. The harvest of the fruits changes according to the cultivated variety; it is possible to say that it goes from around June to September.